Revert "Separate out loop closure information."

pkg/compiler/lib/src/closure.dart

Index: pkg/compiler/lib/src/closure.dart
diff --git a/pkg/compiler/lib/src/closure.dart b/pkg/compiler/lib/src/closure.dart
index 6320e1f7bbaea75450fccf13e2594ab2825f031e..4ba469bf367921d5fb77fbb528febca2c35561d6 100644
--- a/pkg/compiler/lib/src/closure.dart
+++ b/pkg/compiler/lib/src/closure.dart
@@ -30,10 +30,6 @@ abstract class ClosureClassMaps<T> {
   ClosureClassMap getMemberMap(MemberEntity member);
   ClosureClassMap getLocalFunctionMap(Local localFunction);
 
-  /// Look up information about a loop, in case any variables it declares need
-  /// to be boxed/snapshotted.
-  LoopClosureRepresentationInfo getClosureRepresentationInfoForLoop(T loopNode);
-
   /// Accessor to the information about closures that the SSA builder will use.
   ClosureAnalysisInfo getClosureAnalysisInfo(T node);
 }
@@ -54,43 +50,12 @@ class ClosureAnalysisInfo {
   /// Accessor to the local environment in which a particular closure node is
   /// executed. This will encapsulate the value of any variables that have been
   /// scoped into this context from outside. This is an accessor to the
-  /// contextBox that [requiresContextBox] is testing is required.
+  /// contextBox that [requiresContextBox] is testing for.
   Local get context => null;
 
   /// True if the specified variable has been mutated inside the scope of this
   /// closure.
   bool isCaptured(Local variable) => false;
-
-  /// Loop through every variable that has been captured in this closure. This
-  /// consists of all the free variables (variables captured *just* in this
-  /// closure) and all variables captured in nested scopes that we may be
-  /// capturing as well.
-  void forEachCapturedVariable(f(Local from, FieldEntity to)) {}
-}
-
-/// Class that describes the actual mechanics of how a loop is
-/// converted/rewritten without closures. Unlike JS, the value of a declared
-/// loop iteration variable in any closure is captured/snapshotted inside at
-/// each iteration point, as if we created a new local variable for that value
-/// inside the loop. For example, for the following loop:
-///
-///     var lst = [];
-///     for (int i = 0; i < 5; i++) lst.add(()=>i);
-///
-/// The result of `lst` will be [0, 1, 2, 3, 4], whereas were this JS code
-/// the result would be [5, 5, 5, 5, 5]. Because of this difference we need to
-/// create a closure for these sorts of loops to capture the variable's value at
-/// each iteration, by boxing the iteration variable[s].
-class LoopClosureRepresentationInfo extends ClosureAnalysisInfo {
-  const LoopClosureRepresentationInfo();
-
-  /// True if this loop declares any variables that need to be boxed.
-  bool get hasBoxedVariables => false;
-
-  /// The set of iteration variables (or variables declared in the for loop
-  /// expression (`for (...here...)`) that need to be boxed to snapshot their
-  /// value.
-  List<Local> get boxedVariables => const <Local>[];
 }
 
 class ClosureTask extends CompilerTask implements ClosureClassMaps<Node> {
@@ -111,12 +76,6 @@ class ClosureTask extends CompilerTask implements ClosureClassMaps<Node> {
     return value == null ? const ClosureAnalysisInfo() : value;
   }
 
-  LoopClosureRepresentationInfo getClosureRepresentationInfoForLoop(
-      Node loopNode) {
-    var value = _closureInfoMap[loopNode];
-    return value == null ? const LoopClosureRepresentationInfo() : value;
-  }
-
   ClosureClassMap getMemberMap(MemberElement member) {
     return getClosureToClassMapping(member);
   }
@@ -486,8 +445,7 @@ class SynthesizedCallMethodElementX extends BaseFunctionElementX
 
 // The box-element for a scope, and the captured variables that need to be
 // stored in the box.
-class ClosureScope
-    implements ClosureAnalysisInfo, LoopClosureRepresentationInfo {
+class ClosureScope implements ClosureAnalysisInfo {
   final BoxLocal boxElement;
   final Map<Local, BoxFieldElement> capturedVariables;
 
@@ -504,7 +462,7 @@ class ClosureScope
 
   List<Local> get boxedVariables => boxedLoopVariables;
 
-  bool get hasBoxedVariables => !boxedLoopVariables.isEmpty;
+  bool hasBoxedLoopVariables() => !boxedLoopVariables.isEmpty;
 
   bool isCaptured(Local variable) {
     return capturedVariables.containsKey(variable);
@@ -594,9 +552,6 @@ class ClosureClassMap {
     freeVariableMap.forEach(f);
   }
 
-  bool isVariableUsedInTryOrSync(Local variable) =>
-      variablesUsedInTryOrGenerator.contains(variable);
-
   Local getLocalVariableForClosureField(ClosureFieldElement field) {
     return field.local;
   }